Did you know? Minnesota has 11,482 lakes 10 acres or larger, of which 5,483 are fishing lakes. Excluding Lake Superior, the state has 3.8 million acres of fishing water. Minnesota's portion of Lake Superior is 1.4 million acres.

Fry - Newly hatched fish that are ready to be stocked usually called "swim-ups". Walleye fry are 1/3 of an inch or around 8 mm.

Fingerling - Fingerlings are one to six months old and can range from a size of one to twelve inches depending on the species. Walleye fingerlings range from three to eight inches each fall.

Yearling - Yearling fish are at least one year old. A one-year-old fish can range from three to twenty inches depending on the species. Walleye yearlings average from six to twelve inches.

Adult - Adult fish are fish that have reached maturity. Depending on the species, maturity can be reached at two years of age. Walleye reach maturity between the ages of four and six years.

Fish Consumption Guidelines

These fish consumption guidelines help people make choices about which fish to eat and how often. Following the guidelin
es enables people to reduce their exposure to contaminants while still enjoying the many benefits from fish.

Pregnant Women, Women who may become pregnant and Children under age 15

LAKE NAMECounty, DOWID

Species

Meal Advice

Contaminants

Unrestricted

1 meal/week

1 meal/month

Do not eat

FOXMartin Co., 46010900

Bluegill Sunfish

All sizes

Carp

All sizes

Channel Catfish

All sizes

Crappie

All sizes

Mercury

Walleye

All sizes

Mercury

General Population

LAKE NAMECounty, DOWID

Species

Meal Advice

Contaminants

Unrestricted

1 meal/week

1 meal/month

Do not eat

FOXMartin Co., 46010900

Bluegill Sunfish

All sizes

Carp

All sizes

Channel Catfish

All sizes

Crappie

All sizes

DOWID - MN DNR, Division of Waters' lake ID number.

Contaminants listed were measured at levels that trigger advice to limit consumption.

Listing of consumption guidelines do not imply the fish are legal to keep, MN DNR fishing regulations should be consulted.

Status of the Fishery (as of 09/03/2013)

INTRODUCTION

Fox Lake is a 1,041acre lake located in south-central Minnesota near the city of Sherburn in Martin County. Fox Lake has a maximum depth of 20 feet but 75 percent of the lake has water less than15 feet deep. Minnesota lakes managed for fishing are grouped into classes based on physical and chemical similarities and Fox Lake is assigned to lake class 24. Lake class 24 consists of shallower, relatively turbid (brown colored water) lakes high in nutrients that have some shallow water areas and are irregularly shaped (not round). The lake-to-watershed ratio for Fox Lake is 4-to-1, which indicates a small influence of the watershed to the lake. Recent watershed improvements have led to the return of aquatic vegetation in Fox Lake. Water clarity is improving, a 2.6 foot water transparency was observed during the summer of 2013. A Martin County Soil and Watershed District led program started in 2012 is focused on further improving watershed conditions for Fox Lake as well other Martin County Lakes. Improvements in the watershed for Fox Lake will continue to manifest in improved water quality and thereby improved habitat conditions for the fish community.

Like many lakes in southern Minnesota, Fox Lake is managed for walleye and crappie. However, Fox Lake is unique to the Windom Fish management area because it is managed for muskie and it is the southernmost muskie lake in the state, which provides a very unique angling opportunity. In addition, the fish population of Fox Lake has been surveyed by DNR annually since 1991, which has provided an exceptional dataset to understand the fish community with a better ability to focus fish management decisions. Finally, unlike many lakes in southern Minnesota, Fox Lake has never been aerated during the winter and provides a more stable dissolved oxygen profile during winter when compared to other area lakes. Ultimately, Fox Lake has proven to be a valuable and unique resource in southern Minnesota for lakeshore owners, local and regional anglers, as well as general recreational users.

A fish population assessment is conducted each September. The following information outlines the information collected during the latest population assessment in September 2013 using 11 trap nets and 6 gill nets.

WALLEYE

The expected gill net catch rate of walleye in Fox Lake is between 1.2 and 6.3 per net and the expected range for the trap net catch rate is between 0.3 and 1.2 per net. The gill net catch rate in 2013 was 1.8 per net which is within the expected range, but less than desired for Fox Lake based on the lake management plan. The trap net catch rate was only less than 0.1 per net, which was below the interquartile range for Fox Lake. Historically, the Fox Lake gill net catch rate has been sporadic with catches ranging from 0.5 to 45.2 from 1981 to 2001 with an average catch rate of 9.8 per gill net during that same time frame. Since 2002, the catch rates have varied to a lesser degree from 0.5 to 4.0 with an average catch rate of 2.4 walleye per gill net indicating a more stable walleye population. The reduction in the average catch rate from 9.8 walleye per gill net from 1981 to 2001 to 2.4 walleye per gill net from 2002 to 2013 is not easily explainable and is most likely the result of many factors. From 1979 to 2009 Fox Lake has been stocked with walleye fry, fingerlings, yearlings, and adults depending on production. When the catch rate after stocking was analyzed, the highest catch rates were associated with fry stockings in 1983 and 1984 and intensive fingerling stocking in 1992 and 1993. But, suppressed catch rates were also associated with fry and fingerling stocking from 2002 to 2013 indicating other factors may be involved. Since 1998, competition for limited prey resources has never been higher in Fox Lake with the emergence of robust populations of white crappie, black crappie, channel catfish and the decline of black bullhead as a forage base. In addition, muskie have been stocked in Fox Lake starting in 1999 adding an additional predator to compete with for limited prey items (yellow perch, small common carp, small freshwater drum, and seasonally abundant minnow species). Starting in 2010, walleye frylings (2 to 3 inch fish) have been stocked annually (except 2012 when production failed) which led to a slight improvement in gill net catch rates to 3.2 to 3.5 fish per gill net from 2011 to 2012. Given only a slight improvement, competition with other predators appears to continue to suppress the walleye population abundance. In 2013, fingerling walleye were stocked in the fall in addition to frylings in the spring. Monitoring of the walleye population in 2014 will indicate if that stocking was successful. While the catch rates have been suppressed in recent years, the size structure of the population does appear to be improving. The number of 15 inch and larger walleye is increasing. Larger fish are becoming more common and local anglers have even stated that the walleye fishing is the "best walleye fishing in recent years". The walleye in the 2013 sample ranged from 14.8 to 19.5 inches with an average size of 17.7 inches. Additionally, the walleye in the sample were healthy with an average weight above 2 pounds. Future abundance of the walleye population appears directly related to other species given the competition for limited food sources. Improvement of the walleye population abundance will most likely occur if other predator species abundance decreases (crappies, channel catfish, muskie, or largemouth bass). The population appears to be at a level that provides some good fishing opportunities, but less than a population level that makes walleyes the dominant game species in the lake.

MUSKIE

Muskie have been stocked into Fox Lake starting in 1999 with subsequent stockings in 2001, 2004, 2006, 2008, 2010, and 2012. No natural reproduction of muskie has been documented in Fox Lake so all muskie in the lake are from stocking. Year classes present from the stockings are ages 1, 4, 5, 7, 9, 12, and 16. Muskies over 10 years old have the ability to reach trophy size so potential exists for the Fox Lake muskie population to have trophy individuals present in the lake. In 2013, 2 muskies were caught in the gill net sample (a little more than 0.3 fish per net). Muskie are not effectively sampled with gill nets and standard trap nets and the long-term catch rates from 2000 to 2013 reflect that with gill net catch rates varying from only 0 to 0.7 fish per net. Therefore, in 2011 a long-term muskie study was started focusing on obtaining information leading to a population estimate that will help determine the ideal stocking rate for Fox Lake. Large-frame trap nets were used in 2011, 2012, and 2013 in the spring to capture muskie, particularly muskie greater than 34 inches and thus considered mature. In 2011, 140 muskie were caught over 2 weeks in May. The muskie ranged in length from 14.5 to 48.9 inches with an average length of 41.7 inches. In 2012, 45 muskie were caught over 3 weeks in April and May. The muskie ranged in length from 31.0 to 48.7 inches with an average length of 41.5 inches. In 2013, 107 muskie were sampled over 2 weeks in April and May. The muskie ranged in length from 29.0 to 50.4 inches with an average length of 41.1 inches. The population estimate of muskie greater than 34 inches ranges anywhere from 190 to 287 fish with 95% confidence. This indicates the population is doing well and many large muskies are present in the lake. The muskie population will be monitored every other year with large frame trap nets starting in 2015.

CRAPPIE

Two species of crappie are present in Fox Lake, black crappie and white crappie. The catch rates of black crappie were 5.7 fish per gill net and 5.4 fish per trap net and the catch rates of white crappie were 0.3 fish per trap net with no white crappie in the gill net sample. Catch rates of crappie are not necessarily the best indicator of how well the population is doing. Crappie catch rates tend to vary widely from year to year and even from season to season and the population size structure is more indicative of the overall health of the population in the lake. Black crappie ranged in size from 3.2 to 12.7 inches with an average length of 7.3 inches in the gill net sample and 5.9 inches in the trap net sample. More than 60% of the black crappie in the sample were 10 inches or greater and about 35% were bigger than 12 inches. White crappie ranged in size from 10.75 to 11.06 inches with an average size of 10.91 inches. All white crappie in the sample were larger than 10 inches. Overall, it appears that the black and white crappie populations have an imbalanced size structure with most of the fish being larger than 8 inches. An imbalanced size structure can indicate that a year class of crappie is missing from the sample, whether from failed spawning or from bad sampling during the time period of the sample. Future assessments, including potential spring trap netting in 2014 when they are moving near shore, will monitor the black crappie populations to determine if they are truly out of balance or if they were ineffectively sampled in 2013.

YELLOW PERCH

Yellow perch in Fox Lake are the main forage for the walleye and muskie populations. Fluctuations in the abundance of the yellow perch population can lead to fluctuations in the walleye and muskellunge populations. The historical catch rates of yellow perch in the gill nets range from a low of 0.3 per gill net in 1992 to a high of 80.5 in 2012 and from 0 per trap net (1986, 1989, and 1992) to 22.6 per trap net in 1997. The 2013 gill net catch rate was one of the lowest on record at 1.5 fish per gill net which is unusual because the catch rate in 2012 was the highest on record at 80.5 per gill net. A cause in the swing in catch rate from one of the greatest to one of the lowest is not completely understood at this time, but growth of large aquatic vegetation beds over the last 5 years may give the yellow perch a place to successfully hide from survey nets as well as from predators. Increased survival of the yellow perch in Fox Lake as a result of increased vegetation growth will increase the chances of sustaining a consistent abundance of forage sized fish in the lake which will help the yellow perch population sustain itself in addition to sustaining the walleye and muskellunge populations. The size of yellow perch in the 2013 sample ranged from 4.5 to 9.3 inches with an average length of 8.0 inches in the gill net sample and 6.3 inches in the trap net sample. This range of sizes should be adequate as a forage base even if perch are low in abundance. Spawning sized fish remain in the population and successful reproduction in the future may help to boost the forage base and add an additional angling opportunity.

OTHER SPECIES

Other species of fish caught in the 2013 survey were bigmouth buffalo, black bullhead, channel catfish, common carp, freshwater drum, and largemouth bass. Of the species listed above, channel catfish and freshwater drum are the most significant contributors to the fish community in terms of relative biomass (weight of fish available as a relation to the total weight of all fish species in the lake combine). Channel catfish are doing well in Fox Lake and currently range in length from 22.1 to 26.4 inches with an average weight of 5.1 pounds. The abundant channel catfish population is the suspected reason why the bullhead population is not as prevalent as it has been in the past due to predation and competition for common resources. Finally, freshwater drum are the most prevalent "rough" fish in the population with a gill net catch rate of 64.8 fish per net. Freshwater drum in the 2013 sample ranged in length from 3.8 to 18.0 inches with an average of 10.9 inches in the gill net sample and 13.7 inches in the trap net sample. With an abundant muskie and potentially expanding walleye population, small freshwater drum will increasingly become important as prey species for larger muskellunge and walleye.

SUMMARY

Overall, the Fox Lake fish community appears to be doing well with a diverse fish community that is seeing improvements in managed fish species abundance and/or size structure. Further Improvements in the lake for the fish community should focus on best management practices in the watershed. Improvements and education in land stewardship will often have secondary benefits to the lake in the way of quality and quantity of habitat. Generally, improvements in the quality and quantity of lake habitat will result in direct improvements for the fish community. Wise use of our resources makes us good stewards to the land and water that all of us use every day.